delivered the opinion of the Court.
This appeal is from an order of court reversing a decision of the Comptroller and entering a judgment against the Comptroller in the amount of $49,486.40, representing a refund of sales and use taxes previously paid by Fairchild. The facts are virtually undisputed.
On July 1, 1954, Fairchild entered into a “study” contract with the United States Air Force, to determine whether it was feasible, from a technical point of view, to build a certain type of missile and use it as a decoy to confuse enemy radar by simulating an attack plane, the B-52. This project was completed in the spring of 1955. Thereafter, Fairchild submitted various proposals showing manufacturing details *255and estimated costs. On September 21, 1955, an elaborate contract was executed of the cost plus a fixed fee type. This was called the “goose” contract, from the name of the missile. The initial appropriation was $3,550,000.00, with the total cost estimated at some $14,000,000.00. Fairchild was given complete design responsibility, as the prime contractor. Most of the work was to be performed at Hagerstown, Maryland, the assembly point.
The contract was described as a “Research and Development Program for Weapon System 123 A.” Among other things, the contractor agreed to “perform the following services :
Item 1—Conduct a research and development program which will result in the development to completion of a weapon system in accordance with MCPHMS Document, dated 16 June 1955, * * * to include * * * the following:
(a) Provide a full-scale mock-up of the operational weapon system and participate in a mock-up inspection by the Air Force.
(b) Design and manufacture hardware for use in the research and development program, including a quantity of experimental missiles. The configurations and quantity of the hardware (missiles, ground equipment, etc.,) will be such that they are suitable for use in the flight program established by the Contractor. * * *.
(c) Conduct flight test program to demonstrate compliance of the aircraft requirements in respect to range, performance accuracy, and, to a limited extent, simulation. The flight test program will include demonstration of the weapon system ground equipment and launching techniques, * * *.
(d) Provide all the facilities, supplies and services necessary to accomplish Item 1, except for those provided by the Government * * *, including the repair and revision of experimental hardware in order to make tests and retests within the development pro*256gram. Also to be included are the parts and material required for these purposes. The costs incurred by the Contractor in providing such facilities shall be treated as direct costs allocable to the contract * *
There followed other provisions in regard to engineering reports and plans.
Part VI contained a clause: “Inspection and acceptance of physical articles fabricated under paragraph (b) of Item 1 will be at Hagerstown, Maryland.” Fairchild’s project engineer testified that the contract called for not less than fifty-three missiles to be built and flown, the last fourteen to be used for demonstration to the Strategic Air Command. Fairchild set up the operation by subcontracting for the wings and forward fuselage according to its own designs, and subcontracting for the engines and telemetry system. It constructed the vital center section and the after fuselage. Fairchild purchased raw materials and parts from various suppliers on an “F.O.B. vendor’s plant” basis. Title passed to the Government, in accordance with the terms of the “goose” contract, upon delivery to Fairchild at the shipping points of origin, and the Government promptly paid the invoices. Some of the material, such as radio sets and guidance equipment, was supplied by the Air Force and built into the missiles.
The contract was terminated in December, 1958, because of a shift in Air Force strategic policy. At that time twenty-two of the fifty-three missiles called for in the contract had been built and fifteen had been fired in test flights. None of those fired was ever recovered. The information gained from the test flights, conducted at the Air Force Base at Cape Canaveral, Florida, by employees of Fairchild under Air Force Supervision, was used to improve or modify succeeding missiles. At the time of termination the tests had been successful and fully supported the predictions of the earlier study contract. Fairchild expected to receive a large production contract. The unexpended missiles and the ground equipment remained in the possession of, or were delivered to, the Air Force.
The taxes for which refund was claimed, except for a small *257item paid by local suppliers, were paid by Fairchild by way of its own use returns, in conformity with a ruling of the Comptroller given in 1956. They were calculated upon the cost or value of materials actually incorporated into the “goose” missiles, and did not include tools, tooling raw material, machinery and equipment, or overhead items such as office supplies.
Code (1957), Art. 81, sec. 372 (d) provides:
“(d) ‘Use’ means the exercise by any person within this State of any right or power over tangible personal property purchased either within or without this State * * *. This term shall also include but not be limited to use of facilities, tools, tooling, machinery or equipment (including, but not limited to dies, molds and patterns) by a purchaser thereof even though he transfers title to another either before or after use by him and without regard to whether title is transferred to the other within or without this State. This term shall not include the following: * * *
(2) The incorporation of tangible personal property as a material or part of other tangible personal property to be produced for sale by manufacturing, assembling, processing or refining.”
Almost identical language is used in Code (1957), Art. 81, sec. 324 (f) in regard to sales at retail, and we shall treat the two together. The taxes are, of course, complementary. Comptroller v. Glenn L. Martin Co., 216 Md. 235, 242.
The Comptroller concedes in his brief that if the “goose” contract is a contract for the production and sale, or use, of tangible personal property manufactured from the items purchased, rather than a contract for services, Fairchild is entitled to the refund it claims. It is the intent and purpose of the sales and use tax acts “To impose the tax on the final purchaser or ultimate consumer and to avoid a pyramiding of the tax.” Comptroller v. Aerial Products, 210 Md. 627, 644. He contends, however, that the contract was for engineering services and that Fairchild itself was the ultimate consumer *258and. user of the articles purchased. But we agree with the trial court that this contract differs from the ordinary research and development contract in that under the delivery s'ection it specifically provided for inspection and acceptance by the Air Force of each completed missile, to be followed by the test firing in Florida. Perhaps it could fairly be said that the contract was something of a hybrid, but we think the end result contemplated was a series of completed missiles with optimum flight characteristics, and not the usual engineering reports and data only, characteristic of a “study” contract, in the course of which items of tangible personal property are consumed. It may also be observed that a large proportion of the total cost was represented in the finished missile and ground equipment utilized in its launching and tracking. To the extent that the contract called for what is referred to as “hardware”, the materials incorporated therein would seem to fall squarely within the exclusionary language of sec. 372 (d) (2), quoted above. It can hardly be denied that the completed missiles and the ground equipment were delivered to the Air Force and fully paid for by the Government. We think the fact that some of the missiles were expended, by way of test firing, is not controlling.
The Comptroller relies strongly upon the case of United Aircraft Corp. v. O’Connor, 107 A. 2d 398 (Conn.). In that case contracts for experimental engines were held to be for services, on the ground that the delivery of property was merely incidental to a special service performed by the purchaser. There was no finding as to how much of the material bought by the contractor was used and scrapped and how much was eventually incorporated into the engines. At the time of the transactions giving rise to the tax, the Connecticut statute did not contain the language subsequently enacted, excluding materials which become an ingredient or component part of tangible personal property to be sold. The soundness of the decision has been questioned in an article by Hellerstein, in 11 Tax L. Rev. 261, 283. We have distinguished it in two prior decisions. Balto. Foundry v. Comptroller, 211 Md. 316, 321; Comptroller v. Aerial Products, supra. In the later case of United Aircraft Corp. v. Connelly, 140 A. 2d *259486, 491 (Conn.), the statutory exemption was applied, in the case of an experimental contract for aeronautical equipment such as airplanes, aircraft engines and propellers, and it was held that fabrication materials were not taxable, under the statutory exception. The court stated that even under the test of the O’Connor case, the products of the experimentation were the tangible personal property delivered to the Government and “were the end and primary objective of the government.”
Since we hold that the items of material here in question were not subject to the sales or use tax, we do not reach the contention of the appellee that, since title passed to the Government upon delivery of each item, the doctrine of immunity applies. The appellant contends that the amendment of sec. 372 (d), and sec. 324 (f) (6), by chapter 3 of the Acts of 1957, imposed a tax upon “facilities”, even though the contractor transferred title to another before or after use by him. Even assuming that the passage of title to the Government would not prevent the imposition of a tax based on the subsequent use made by the contractor (see Martin Co. v. State Tax Comm., 225 Md. 404, 415-417), the Maryland statute clearly imports that where materials are incorporated in a manufactured or assembled product, the tax should be paid by the ultimate consumer. In the absence of Congressional consent, such a tax cannot be levied against the Government itself. It could hardly be contended that the nature and theory-of the tax is altered by the fact that the ultimate consumer is. immune. Nor do we find any reason to extend the term “facilities” beyond its context, where it is associated with “tools,, tooling, machinery or equipment (including, but not limited to dies, molds and patterns)”, so as to nullify the express, provision excepting tangible personal property purchased for incorporation “as a material or part of other tangible personal property to be produced for sale by manufacturing, [or] assembling, * * As we pointed out in Balto. Foundry v. Comptroller, 211 Md. 316, 319, we are not here dealing with an exemption, but with a definition of the scope o.f the taxing statute. As we construe the “goose” contract, the Government,. *260and not the contractor, was the ultimate consumer of the missiles delivered and accepted, along with the appurtenant ground equipment, into which the property, now sought to be taxed, was incorporated.
The appellee complains that the trial court disallowed interest upon its claim, but in the absence of a cross-appeal we think the point is not properly before us. Cf. Fitch v. Double “U” Sales Corp., 212 Md. 324, 329, and cases cited.
Judgment affirmed, with costs.